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Institution

DECHEMA

NonprofitFrankfurt am Main, Germany
About: DECHEMA is a nonprofit organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Corrosion & Oxide. The organization has 756 authors who have published 1307 publications receiving 25693 citations.
Topics: Corrosion, Oxide, Coating, Alloy, Catalysis


Papers
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PatentDOI
30 Sep 1967
TL;DR: Niobium may be partially replaced by tantalum on an atom for atom basis up to a maximum content of tantalum of 0A1%. The alloy may be solution treated at 1040 - 1080 C and aged in a single step, at 700-760 C or in two steps at 740-780 C.
Abstract: 1,132,724. Ni-Cr-Fe alloys. HENRY WIGGIN & CO. Ltd. Sept.26, 1967 [Oct.3, 1966], No.44114/66. Heading C7A. Nickel-chromium-iron alloys comprise: - C 0A02 - 0A1% Al 0A25 - 0A75% B 0A003 - 0A02% Cr 11 - 16% Mo 4 - 7% Ni 35 - 45% Nb 0A3 - 0A8% Ti 2 - 3A5% optionally Zr up to 0A1% the balance, apart from impurities (e.g. up to 0A5% each of Mn and Si), being iron. Niobium may be partially replaced by tantalum on an atom for atom basis up to a maximum content of tantalum of 0A1%. The alloy may be solution treated at 1040 - 1080‹C. and aged in a single step, at 700-760‹C. or in two steps at 740-780‹C. and then at 675-720‹ C. The alloys may be used for rotor discs in gas turbines.

3 citations

Journal ArticleDOI
Michael Schütze1, M. Malessa1
TL;DR: The European COTEST research project was started with 23 participants from 11 countries including representatives from industry, universities, private institutes and national research labs and the development of a comprehensive set of guidelines serves as a basis for a future ISO standard for this type of test.
Abstract: The cyclic oxidation test is the most often used tool in industry to characterise the high temperature oxidation/corrosion resistance of technical materials in the laboratory. In the past, however, there has been the problem of a lack of intercomparability of data from different laboratories and sometimes even from different test runs in the same lab since no general guidelines or standards were existing for this type of test. Being aware of this situation the European COTEST research project was started with 23 participants from 11 countries including representatives from industry, universities, private institutes and national research labs. The present paper reports about the outcome of this project after three years. The project consisted of 8 work packages including literature search on the state-of-the-art at the beginning of the work, experimental investigations supported by a statistics approach in order to quantify the impact of the different test parameters on the test results, a validation testing phase and the development of a comprehensive set of guidelines. The latter is available on the internet and serves as a basis for a future ISO standard for this type of test.

3 citations

Journal ArticleDOI
Ingo Ehmann1, Ewald Heitz1
TL;DR: In this article, a discussion on the chemo-mechanical load demonstrates the significance of hydrodynamics in selecting the test method, choosing a pipe with an abrupt expansion of cross-section as a flow model yields a new method of simulating operation conditions.
Abstract: The transport of corrosive liquids containing solids, in conventional energy and process technology as, for example, in oil and gas production, places high demands on the selection of materials for plant construction. A discussion on the chemo-mechanical load demonstrates the significance of hydrodynamics in selecting the test method. Choosing a pipe with an abrupt expansion of cross-section as a flow model yields a new method of simulating operation conditions. By subjecting ferrous materials used for hydraulic machinery to representative media from three important industries, a broad spectrum of results can be obtained. Classification of the results leads to four basic types of mass loss behaviour in materials as functions of flow rate. These findings yield guidelines for the selection of materials and the dimensioning of flow equipment.

3 citations

Journal ArticleDOI
Hans Kral1
TL;DR: In this paper, a theory which contains the Arrhenius parameters cannot be established for the entire system (whole temperature range) on the basis of classical logic, and only the subsystems can be consistent and complete.
Abstract: The interpretation of the term “compensation” obscures a logical contradiction, the catalytic paradox, which is caused by inconsistent validity ranges of the Arrhenius parameters, the pre-exponential factor and the activation energy. For this reason, a theory which contains the Arrhenius parameters cannot be established for the entire system (whole temperature range) on the basis of classical logic. Only the subsystems can be consistent and complete. One subsystem is the range of the topocatalytic concept which is relevant for thermal deactivation, thermal bistability and for all reactions with surface dependence of activity. The other is the range of the energetic concept which is preferred in fundamental research. In order to complete the subsystems, new consistent symbols are introduced. The change of particle size caused by thermal deactivation can result in four possible particle size effects, two of which have been discussed in the literature.

3 citations


Authors

Showing all 760 results

NameH-indexPapersCitations
Wolf B. Frommer10534530918
Michael W. Anderson10180863603
João Rocha93152149472
Martin Muhler7760625850
Michael Hunger6029511370
Ivars Neretnieks442247159
Michael Schütze403436311
Jens Schrader381294239
Roland Dittmeyer312063762
Lei Li291984003
Dirk Holtmann291073033
Lasse Greiner26741994
Klaus-Michael Mangold23571590
A. Rahmel23591967
Gerhard Kreysa22781305
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
20231
20227
202145
202053
201949
201844